In continuous processes of treating or otherwise working with webs, it is necessary to splice the surface of a web carried by a new roll to the surface of the web leading from an expiring roll without interrupting the movement of the web to the installation at which operations are being performed thereon.
Apparatus is known in the prior art for automatically achieving the operation of splicing the surface of a new roll web to the surface of a web leading from an expiring roll. In apparatus of this kind, in the normal course of operations the web extends from the roll stand over a splicing unit bumper roll in its inactive position to a web tensioning system. To control the web tension the tensioning unit normally provides an output signal which is applied to a brake on the spindle of the roll being unwound. In preparation for a splicing operation, the roll-supporting turret is brought to a location at which a new roll is loaded onto a pair of empty arms on the turret. Next, the leading edge of the new web is torn to form a V therein at a predetermined location around the roll. Adhesive is applied to the surface of the web along the edge of the V and tear strips are used to hold this free edge down onto the remainder of the web. Next, the turret is moved in a direction to bring the new roll to a position at which it will be adjacent to the surface of the bumper roll of the splicing unit in its ready position. Next, the new roll is driven to bring it up to line speed. When this has been achieved, the operator notes the expiration of the web on the old roll and at a predetermined time operates a push-button to "fire" the bumper roll by pivoting it to bring the expiring web into contact with the web on the new roll. When that occurs, the new and old webs are adhered and the new web is caused to move along with the old web as the tear strips break. Shortly thereafter, a knife bar is swung from its ready position to an active position, in the course of which movement it severs the tail of the old web. The splice is now complete. Subsequently, the old roll is stopped, the tension system braking signal is applied to the new roll spindle, the bumper roll and knife bars return to their ready positions and the entire splicing unit is retracted.
Manufactured webs of paper, plastic and the like, are never identical on the two sides thereof. Moreover, as supplied by the manufacturer, the same side of the web always is in on the roll. In some web treating or assembling process of the prior art, it is desirable to work with one side of the web up, while in other processes it is desirable to work with the other side of the web up. Automatic splicing arrangements of the prior art generally are capable of performing only a splice of one type. That is to say they permit of use of an installation in which only one side of the web being unwound can be up. More particularly, there is known in the prior art, for example, an apparatus which is adapted to perform an undersplice, which is splicing the inner surface of the expiring web to the outer surface of the web on the new roll in an arrangement in which the inner surface of the web being unwound is up in the subsequent process. If it were desired to have the outer surface of the roll as applied by the manufacturer up in the process involved, it would be necessary to rewind the roll first in order to use this splicing apparatus, or in some manner invert the travelling web as it moved toward the process installation. While units capable of performing both an undersplice and an oversplice are known in the prior art, such units are cumbersome and changing over from an undersplice to an oversplice and vice versa with such units is a relatively complex operation.
We have invented an improved automatic web splicing apparatus which is adapted to perform either an undersplice or an oversplice. Our apparatus accomplishes this result which being less cumbersome than are alternate side splicing units of the prior art. Our apparatus may rapidly and expeditiously be changed from a condition in which it performs an undersplice to a condition in which it can perform an oversplice. It is relatively simple in construction for the results achieved thereby.